i had exactly the same idea and built mine over the weekend, i was coming here to post my idea only to find you got there first!

ahh well, its a great case for what i need (cheep) and keeps things from falling onto the PCB (my main worry as its going to be around the back of my TV)

its a very simply built - just dremmel out some holes for the ports you want (remembering you will want to put the board down and then slide forward (for the USB to stick out the case - so the audio aperture needs to be elongated to allow for this travel) and then cut the lid so when its fitted it doesn’t clash

i couldn’t upload any high res images to the forum (restrictions on size) so thery are here if anyone’s interested